A digital television or video receiver such as a television, set top box or the like has inherently long channel change times due to the complexity of the television signal. Particularly, digital television signals are compressed in order to eliminate redundancies from line to line and from frame to frame in the television images. The compression technology utilized in digital television systems makes the incoming television signal difficult to decode and display.
The incoming digital television signal must undergo extensive processing before it can be provided for display. At the least, the digital television signal must undergo tuning, demodulation and decoding before it is encoded for presentation on a display device. Thus, while the complex encoding scheme for digital television signals produces a high quality television picture, the complex encoding scheme also causes a delay in the reproduction of a video signal. Since a change in channel requires the digital television signal to undergo the same tuning, demodulation and decoding procedure, there is a consequent delay in providing the video signal after a channel change request.
Recently, devices known as digital video storage devices or personal video recorders have been introduced. Personal Video Recorder (PVR) is a generic term for a device that records television data in digital format in a storage medium, such as a memory or hard disk drive, and may also be referred to as a hard disk recorder (HDR), digital video recorder (DVR), personal video station (PVS) or personal TV receiver (PTR). Digital video storage devices utilize the storage medium to record and store television programming as selected by the user. Because of its design, the PVR provides a number of features and functions. One such feature is known as live-pause. Live-pause allows the user to pause live television programming. Live-pause, however, requires the digital bitstream to be stored, read and decoded before viewing, even for a live program. Therefore, it can be seen that a hard drive based digital video recorder adds delays since the viewed program is always previously recorded data in order to make the live-pause feature possible. This adds additional delay to a channel change time.
Despite the increasing availability of on-screen program or channel guides, channel surfing continues to be the method of choice for viewers. A one-quarter to one-half second delay during each channel change makes channel surfing tedious.
It can therefore be appreciated from the above that there is a need to provide for faster channel change in a digital video apparatus.